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3 Sheets-Sheet 1.

(No Modl.)

M. B. MILLS.

GATE FOB RAILWAY GROSSING$. N0. 380,447. PatentedApr. 3, 1888.

s sheets-sheet 2..

(No Model.)

M. B. MILLS.

GATE FOR RAILWAY GROSSINGS. No. 380,447. Patented Apr. 3, 1888.

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GATE FOR RAILWAY onossmes. No. 380,447. PatentedApr. 3, 1888.

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-ated, together with others incident to them,

. UNITED STATES PATENT FFKQEO MORTIMER B. MILLS, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE PNEUMATIC GATE COMPANY, OF SAME PLACE.

GATE FOR RAILWAY-CROSSINGS.

SPECIFICATION forming part of Letters Application filed May 6, 1886. Serial No. 201,354.

T0 all whom a't may concern.-

Be it known that l, MORTIMER B. MILLs, a citizen of theUnited States, residingat Chicago, in the county of (look and State of Illinois, have invented certain new and useful Improvements in Gates for Railway-Crossings; and I hereby declare the following to be a full, clear, and exact description of the same.

The subject of the present application is an improvement upon a device for a similar purpose for which Letters Patent of the United States No. 301,589, dated July 8, 1884:, were granted jointly to myself and \Villiam Hanley.

It is my object to provide gates to be operated in one respect like those described in the aforesaid patent, either all simultaneously or one at a time, and which may be operated and controlled by the operator with great ease and precision by working very moderately the handle of a suitable pump connected with the arms forming the gates through the medium of mechanism suitable for the purpose.

Gates of the foregoing nature are at the presout time and are becoming more and more an indispensable requirement for railroads, and many of different forms of construction and consequent manners of operation are in use, which, however, present various causes for objection to them, among which may be mentioned as principal objections that the mechanisms by means of which the gates are operated get out of order very readily from causes against which their natures will not admit of infallible remedies, or that they are complicated, and hence expensive of construction and unreliable for satisfactory operation, or cannot be properly controlled in their movements by the operator, or are operated only with the exercise of great exertion, and it is believed that one or more of the foregoing dihlcnlties may be found to attend, in greater or smaller degree, the use of any of the gates of the de scription referred to now in operation.

The mechanism, hereinafter described and claimed, which I provide for operating the vertically-swinging arms of railroad-gates constitutes my invention, and affords means whereby the objections hereinbefore enumerare, at least in very great measure, overcome.

Patent NO. 380,447, dated April 3, 1888.

(No model.)

Referring to the drawings, Figure l is a perspective view of a railway-crossing provided with gates operated by my improved mechanism; Fig. 2, a broken vertical sectional view of two posts connected to cause the gate-bars which they support to operate simultaneously, and showing the mechanism which operates directly to actuate the gate-bars; Fig. 8, a view in elevation, taken on the line 3 3 of Fig. 2, of an air-cylinder and parts of a chain operating the piston thereof, the operative position of the cylinder being within a post; Fig. 4c, a vertical sectional view of a valve of particular construction; Fig. 5, a horizontal section of the same, taken on the line 5 5 of Fig. 4, and viewed in the direction of the arrows; and Fig.

6, a similar view to that presented in Fig. 2, showing modifications.

A (see Fig. 1) is a hollow post on one side of a railway-track in line with a similar post, A, on the same side of the track and A is a post, the exact counterpart of the post A, on the opposite side of the track in line with a similar post, A, on the same side with it. Each post A and A contains or is provided with two compressed-air cylinders, B and B, supported to hang vertically upon opposite sides of the posts, and each cylinder is preferably open at its lower end and contains a piston, t, having its rod 8 projecting downward below the open extremity of its cylinder and secured to the lower cross head of an oblong rectangular frame, 7', Fig. 3, the side bars of which are confined to move vertically within guides Q, projecting from opposite sides of the cylinders or from the supports for the cylinders in the form of annular bands 19, as shown. Each frame 1 is sufficiently long to permit to the piston which it controls the full length of its stroke without causing the cross heads to 0 come into contact with the ends of a cylinder. Bars are provided upon the posts and arranged to open and close on opposite sides of the track by swinging with the shafts supporting them in the usual manner of such con 5 trivances. The bars may, if desired, be hung upon their pivotal supports to be balanced when in a horizontal position, and means may be provided for effecting this equilibrium by weighting the short ends of the bars, as shown. [00

A pulley, O, is secured centrally on the shaft of each bar to move with it, and an endless chain, E, surrounds and is secured upon the pulleys within posts in line with each other on the same side of the track, proceeding from the piston-rod of one cylinder, B or B, to which it is secured, around pulleys 0 toward the lower end of each post through a suitable conduit, D, around the pulley in the opposite post, to which pulley it is fastened by means of a pin, n, and back over other pulleys 0, properly located, to the piston-r0d of the adjacent cylinder, B or B. The pistons of the two cylinders are connected together by means of a chain attached at opposite ends to the upper cross-head of each frame r and passing over and fastened by means of a pin, n, upon the pulley 0 within or upon the post containing the cylinders. It will thus be seen that the chain E, though not actually, is practically continuous, since the frames 1" form connecting-links. It is, however, not necessary that the device E shall comprise a chain formed of stout links, as shown, since it may be preferred to provide rods as connecting links to lie within the conduits D, and such rod portion of each chain E may extend nearly the entire length of the conduits D, since the play in a vertical plane of the pulleys Gis obviously required to be only limited. In place of the pulleys O, I use segments of the peripheries of wheels secured on opposite sides of the shafts carrying the bars, and upon which the chain is fastened, as shown in Fig. 6. This construction, although an equivalent of the pulleys C shown, may be preferred to the latter, as it affords convenient means to take up slack in the chain.

The gates are operated by mechanism, hereinafter described, situated in the operators cabin, as shown in Fig. 1 of the drawings, and communicating with the posts A and A into the top of one cylinder ofeach of which it serves to force air, thus lowering the pistons contained in these cylinders, and, owing to the chain-connection, raising the pistons in the other cylinders, whereby the bars of each gate are, owing to the manner of chain-connection shown, moved in a vertical plane toward each other to form or close the gate, or from each other to raise the bars in opposite directions, as the case may be, details in the operating mechanism being such as to permit the lowering or raising and controlling of the bars forming one gate independent of those forming the other.

The mechanism referred to is of the following description: F is an air-pressure pump of common construction, containing a piston operated by a handle, m, and provided on one side at its lower end with an aperture closed.

insidethepump-cylinderbyaninwardly-opening check-valve and on its opposite side, in line with this aperture, a similar one controlled by a check-valve opening outward. A pipe, Z, connects the pump F from the opening therein last named with a T-j'oint, k, in a horizontal pipe, Z, having a diameter, like the pipe Z, preferably of about threeeighths of an inch, and upon each extremity of the pipe Z is secured the shell G of a three-way valve, G, Figs. 4 and 5, and openings are provided in the shells G, from one of which shells pipes t and i, preferably of the same diameter as the pipe Z, lead into the tops of the respective cylinders B and B in the post A, and from the other of which similar pipes, h and h, leadin like manner into the respective cylinders B and B in the post A Communication is thus afforded between the pump F and cylinders in the posts A and A and is capable of being opened or closed through one or all of the pipes it"h h by means of the three-way valve G.

The operation of my improved device depends upon my peculiar construction of the three-way valve G, which I do not claim, broadly, in the present application, as it will form the subject of a separate applicationfor Letters Patent; and to enable the effect of the latter to be readily understood the opera tion, or, rather, lack of operation, in the present connection of an ordinarythree-way valve may be described, in which but a very slight but very important feature is added to render it suitable for the purpose.

Supposing the bars to occupy the positions illustrated in the drawings, downward pressure upon the piston-head of the cylinder B in each or either post A A would operate to raise the bars of each or both gates, and obviously, when raised, downward pressure upon the piston-head t of a cylinder or cylinders, B, would lower the bars. The firstnamed operation, to raise the bars of both gates simultaneously, would be effected by turning the valves by means of both handles 9 g (suitable stops being provided to prevent turning them too far) to the positions in line with each other shown in Fig. 1 of the drawings. valve are thereby brought to coincide with the pipes h Z andt' Z, and by operating the pump F air is forced into both cylinders B against the upper surfaces of the piston-heads ttherein. This operation should cause the pistons in the cylinders B to descend and raise the pistons in the cylinders B, thereby raising the gate-bars; but as communication from the cylinders is closed, since the third opening, 00 in the three-way valve is closed, owing to its position in the shell, there would be no outlet for the air in the cylinders B and pipes communicating with them, and thus an aircushion would be formed, preventing the full The openings :20 m, Fig. 5, in theobviate the foregoing consequence, I drill a hole, f, through the shell G directly below the point of communication with it of each pipe It h and i i, and provide the back of the valve G, or that portion devoid of an opening and directly opposite the opening 00 with a recess, H, leading to each hole f when turned to vertical coincidence with it, as shown in Figs. 4 and 5, and thus the consequence above set forth is avoided, since the air in the cylinders B and pipes leading thereto can escape by way of the recess H through an opening f communicating with it in the shell G.

It is obvious that to lower the bars by in troducing air-pressure from the pump F upon the pistonheads in the cylinders B the pistons in the cylinders B must be permitted to rise. lhis is accomplished by turning the handles 9 from thQll'mPOSliilOHS shown to cause them to extend backward parallel with each other, whereby the pump communicates with the cylinders B, and escape is provided by way of the recesses H in the valves Gthrough the holesfbelow the respective points ofjunction with the shell G of the pipes h and 2'.

hen the gates are down or up, either may be operated independently of the other by turning only the handle 9 which controls the communication to the post containing the cylinders B B on the side of the track where the bars are desired to be actuated, and the latter may be instantaneously arrested at any point of their ascent or descent by turning the valve controlling them, and, if desired, their motion reversed by operating the pump after turning the valve.

From the foregoing description it will be seen that I have provided a device operated by mechanism of extreme simplicity, and its accuracy and ease of operation have been most satisfactorily demonstrated by a full-size working device, in which a length of about one hundred and fifty feet of pipe leading from -the pump mechanism to the farthest post, A

is provided. Air is the actuating medium preferably employed, since it is obtainable without cost, does not require to be stored to afford a supply, and may be wasted without regard. Other forms of gas, though, could be used to produce equally good operation of my device. Liquids, however, would be as impracticable, if not intrinsically useless, as a means for operating my improved gate as they must be for other gates purposely constructed to have their bars actuated exclusively by pressure exerted through them, and this for the reasons principally that liquids require to be stored to afford conveniently-located supply, that they are liable to freeze in the pipes, thereby entailing well-known disastrous consequences, and that to transmit pressure through them as a medium requires the exertion of verygreat power atthe pump, which must be increased in proportion to the distance through which they have to operate,owing to the excessive friction produced.

If desired, the cylinders B may, especially to permit the use of narrower posts, be placed in the posts A and A, their pistons forming links in the chains E at the sides thereof, re spectively, adjacent to the posts A and A, as shown in Fig. 6.

Although two gates only are shown and described in the present application, it is quite obvious that any number of gates may be operated by one pump of adequate size, since each gate is controlled by a single valve, by providing the mechanism described on each pair of posts A A and A" A, connecting the pump in the manner hereinbefore set forth, and providing a three-way valve of my improved construction.

lVhat I claim as new, and desire to secure by Letters Patent, is

1. A gate comprising upon opposite posts swinging bars connected together to cause the rise or descent of one bar to raise or lower with it the other, air-pressure cylinders each having its piston connected with the swinging bar on a post at one side of the axis, as described, and air-pressn re mechanism to e-etuate the piston of one cylinder at a time in one direction, whereby that of the other cylinder is simultaneously actuated in the oppoposite direction, substantially as and for the purpose set forth.

2. A gate comprising upon opposite posts swinging bars connected together to cause the rise or descent of one bar toraise or lower with it the other, air-pressure cylinders each having its piston connected with the swinging bar on a postat a side of the axis, as described. and air-pressure mechanism controlled by a suitable valve to actuate the piston of one cylinder at a time in one direction, whereby that of the other cylinder is simultaneously actuated in the opposite direct-ion, substantially as described.

3. A gate comprising upon opposite posts swinging bars connected together to cause the rise or descent of one bar to raise or lower with it the other, air-pressure cylinders each ICC having its piston connected with the swinging bar on a postat one side of the axis,as described, air-pressure mechanism to actuate the piston of one cylinder at a time in one direction, whereby that of the other cylinder is simultaneously actuated in the opposite direction, and a three'way cock for controlling the airpressure mechanism, and comprising a shell, G, provided with holes f, and a valve, G, provided with openings :20, x, and 02 and with a recess, H, substantially as described.

4. A. gate comprising bars supported upon opposite posts,to which the bars are pivotally connected-toward their rear ends to swing in a vertical plane, an endless connecting device adjusted upon the axis of each bar to cause the rise or descent of one bar to raise or lower with it the other, and air-pressure cylinders within one post on opposite sides of the axis of the swinging bar, each having its piston forming a connecting-link in the endless connecting device, in combination with an air-press ure pump communicating with the cylinders, and a valve within the connecting-passage constructed to afiord communication simultaneously of the pump with one cylinder and of the other cylinder with the external atmosphere, as and for the purpose set forth.

5. A gate comprising vertically-swinging bars supported upon and moving with axes cured upon the pulleys O and over pulleys o, suitably located within the posts A and A and containing the frames r as connectinglinks, an air-pressure pump, F, communicating with the cylinders B and B above the pistons t therein through pipes Z, t, and i, and a three-way cock within the pipe 1', comprising a shell, G, provided with holesf, and a valve,

G, provided with openings 00, x, and m, and

with a recess, H, the whole being constructed and arranged to operate substantially as and for the purpose set forth.

MORTIMER B. MILLs.

In presence of- MASON BRoss, EDWARD THORPE. 

